With no well or municipal tie-in, the water for the home is supplied entirely by rainfall using a Rain Man Waterworks system consisting of two above-ground 10,000-gallon tanks that store runoff from the metal roof. Water is pumped through a two-stage micron filter before passing through an ultraviolet purifier and into the house’s supply line. Wastewater is treated on site and sprayed back onto the landscape. 512.351.5150. www.rainharvester.com
Given the humid climate, the architect specified moisture-resistant fiber-cement materials from James Hardie for upper-story siding, trim, and soffits. The surfaces are finished with Duckback Woodperfect Series Semi-Transparent Coating, a locally sourced low-VOC stain. James Hardie: 888.542.7343. www.jameshardie.com
First-story walls consist of 8-inch-thick autoclaved aerated concrete block from Xella AAC Texas and the company’s proprietary stucco exterior finish. The blocks, which contain small air pockets, provide thermal mass and superior insulating values (R-18 in Austin). The concrete blocks emit no VOCs and eliminate the need for pesticides to control termites. On the upper story, 2x6 wood framing is sprayed with BioBased’s Greenguard-certified closed-cell polyurethane insulation foam. Xella AAC: 888.729.3552. www.xellatexas.com BioBased: 800.803.5189. www.biobased.net
Photovoltaics and Roofing
Sixteen Sharp modules deliver 3.3 kWh of electricity, and a Fronius IG inverter ties the panels to the grid. With the addition of a solar hot water heater from TechSun Solar, the sun supplies about 80% of the household’s energy needs. Sharp: 800.765.2706. www.solar.sharpusa.com Fronius USA: 810.220.4414. www.fronius-usa.com TechSun Solar: 866.765.2763. www.solarme.com The standing-seam galvanized metal roof lasts 40 years, about the life span of the solar arrays. Its U panels were made from readily available mill stock and crimped on-site. Deep overhangs protect doors and windows from the elements, reducing utility and maintenance costs.